It is amazing to me that so many others had great luck with Dominators, all of mine frustrated me to no end. I usually played solo and honestly, I never learned all the tricks for each AT, but some of them worked so much better for me than others. Maybe is was just the RNG playing with my head.
Plant/fire dom was actually one of the best builds in the game, min/maxingwise.
Melee characters in general just weren't for me. My philosophy is: "If you're close enough to touch the enemy, then they're close enough to touch you - and that's too close!" I tried to ensure range 100 (at least) for all my powers and keep my distance, hovering with Fly, ready to escape if things went badly.
Had a dark/shield scrap, a Widow, a claw/dark scrapper, a ninja/ninja stalker, a titan/elec, SS/fire, and a STJ/regen scrapper for melee characters, i'm probably forgetting a few.
Titan/elec couldn't really die because everything it fought got sapped, it had infinite energy, and defensive sweep really made it hard to hit.
Dark/shield murdered entire packs (Including bosses) in about two seconds.
Claws/dark could not die when I got cardiac alpha (Before that...*Shiver*)
Nin/nin was softcapped, and could handle itself fairly well, since bosses died really quick.
Widow was sort of like playing a more badass claws character with psychic powers and a laughably easy softcap...Kickass.
SS/fire/fire- Remember how I said dark/shield cleared entire packs in 2 seconds? This guy cleared entire maps in mere minutes.
STJ/regen: Liked STJ, but I didn't feel like it meshed with regen at all. My worst melee character, not fun, (Subjective, I know) and lacked some damage on the AOE front.